Wearable sensor for continuous monitoring of physiological parameters

Abstract

Providing high quality health care to a mass population is becoming one of the great endeavors of modern society. In order to do so, there is a urge to embrace the use of new technologies that can provide comfort while ensuring the safety and reliability of traditional methods. The system hereby proposed ought to be capable of monitoring a person's vital signs therefore being very flexible regarding its application scenarios. It can be used not only in emergency wards and screening diseases but also in a home environment to monitor elderly people or young children. Furthermore, it is not exclusive to monitoring and preventing diseases, it can also be an instrument that aids sports training at high intensity levels. This product can measure a patient's heart rate and oxygen saturation levels ensuring comfort and easy usage. Another advantage when compared to traditional machines used to fit the same purpose is the fact that it is much cheaper, takes up less space and it encompasses two functional- ities that are otherwise measured with different machines. This system has two major components, an ESP32 microprocessor and a MAX30100 Pho- toPletysmoGraphy (PPG) sensor. The ESP32 module was chosen due to its computing capacity (dual-core 32-bit processor), having a WiFi module built in with full TCP/IP stack and having 3 pre-defined sleep modes to reduce power consumption. The MAX30100 sensor was picked because it is a compact and small module with simple usage. Furthermore, the goal of this disser- tation is to build this system to be energy efficient, maximizing its battery life while not compro- mising its logical correctness. The configuration chosen that produced steady results whilst consuming lowest energy possi- ble was: 37 mA of current for the IR LED, sampling frequency of 50 Hz and pulse width of 200 μs.